1. Field of the Disclosure
The present disclosure relates to interactive projection systems. In particular, it relates to entertainment projection systems to provide an illusory reality to the observer.
2. General Background
Current touch screen systems permit companies to provide their customers the ability to instruct interactive systems by simply touching a surface. Examples are the touch-screens often mounted on computer displays, or the various touch screens used to indicate pointing in connection with automatic teller machines, industrial controllers, entertainment, transportation, etc.
Various X-Y position measurement systems are typically used to determine the position of a finger, or a stylus on their surface. For instance, in resistive type touch-pads the position of a finger provides the “wiper” location in a voltage dividing potentiometer. The divider is formed by a resistive membrane that is shorted to a conductive layer where the finger presses against the resistive membrane. It then becomes possible to measure the resistance of the divider formed by the finger's position relative to the edges of the membrane. In the case of a capacitance sensing system, the same general principle is employed except the fingertip position is determined by a capacitance divider effect.
Current systems can generally detect only a single touch, and cannot distinguish or disambiguate two fingers placed on the surface simultaneously. Indeed, two-fingertip touches are often interpreted as a single event at the geometric center of the two points of contact.